1. Field of the Invention
Embodiments of the invention generally relate to electronic device packaging, and more specifically, to decoupling capacitors for interposers.
2. Description of the Related Art
An interposer is a substrate upon which one or more integrated circuits are disposed. When multiple integrated circuits are disposed on an interposer, the interposer may provide an electrical connection therebetween. In order to reduce the path length of electrical current between the integrated circuits, thereby improving efficiency, it is desirable to position the integrated circuits in close proximity to one another on the interposer. However, signal noise and current leakage due to the shifting of transistor state in one integrated circuit negatively affects the performance of adjacent integrated circuits.
Previous attempts to decrease the signal noise and voltage current between integrated circuits have included the formation of a decoupling capacitor on an interposer. The decoupling capacitors include a first metal layer, an electrically-insulating layer disposed on the first metal layer, and a second metal layer disposed on the insulating layer. The metal-insulator-metal decoupling capacitors are relatively expensive, however, due to the material cost of the metal layers. Additionally, the metal-insulator-metal decoupling capacitors do not provide sufficient decoupling of the integrated circuits because the metal-insulator-metal decoupling capacitors have relatively low capacitances.
Therefore, there is a need for a capacitive device for interposers having a higher capacitance and a reduced manufacturing cost.